In 1.66, I played through the mission with no problems. Replaying mission in 1.68, I get the same problem as described here. Vehicles will not move beyond ambush point near chapel; they will not move to warehouses at point Yankee. Secure Warehouse task will not complete even though all AAF are dead. Mission will not proceed.

Indeed very annoying. I've had exactly the same problem. Just wanted to add:

When the teamleader tells your squad and the APCs to move up, the last APC does indeed move up a little bit until a set distance between the next vehicle (SUV) and itself.
The front APC just opens its hatches and the gun stays aimed to the left (180 degrees from the chapel where the ambushing AAF soldiers were).